You might think it a fool’s errand to attempt programmes about art on the wireless. How can you talk about pictures or sculptures or any other visual form without being able to see them? But features on artists and their work can have a surprising resonance on radio precisely because without any images the programme-makers and their listeners are forced to work harder, and to look beyond the canvas to the back story, the purpose of a self-portrait, a seascape, a domestic interior.